scholarly journals Mass-Charge and Energy Spectra of Oxygen Ions in a Two-Element Laser-Produced Plasma

2008 ◽  
Vol 2008 ◽  
pp. 1-5 ◽  
Author(s):  
R. T. Khaydarov ◽  
U. S. Kunishev
Keyword(s):  
Laser Radiation ◽  
Heavy Elements ◽  
Energy Spectra ◽  
Heavy Component ◽  
Main Attention ◽  
Plasma Ions ◽  
Oxygen Ions ◽  
Target Composition ◽  
The Given ◽  
Flight Measurements

Using a static mass spectrometer, we study the characteristics of multicharge plasma ions generated from solid targets under the action of a 15 nanosecond Nd:YAG laser radiation with maximal intensity 1011 W/cm2. We consider two-element solid targets with a mass of the heavy component ranging from 44.9 (Sc) to 174.9 (Lu) with main attention to the properties of oxygen ions. The time-of-flight measurements show that oxygen ions are obtained in the range of the energy E = 40–250 eV with maximal charge Zmax=2. The latter is independent on the target composition for the given intensity of the laser radiation. However, the properties of the energy spectra of oxygen ions strongly depend on the second component of the target, which is explained by the interaction between the light and heavy elements of the target.

Study of Energy Spectra of Turbulence by the Vortex Method

2004 ◽  
Author(s):  
Yoshifumi Ogami
Keyword(s):  
Shear Layer ◽  
Wave Length ◽  
Vortex Method ◽  
Energy Spectra ◽  
Integral Scale ◽  
Velocity Fluctuations ◽  
Integral Scales ◽  
The Given

The energy spectra produced by the vortex method are studied. The strengths of the vortices are determined so that the energy spectra correspond to the given target spectra for two different integral scales. Velocity fluctuations produced by the simulation of vortex shear layer are obtained and energy spectra of these fluctuations are examined. It is found that in the case of the larger integral scale, the spectra almost agree with the target in the range up to the cut-off wave length, and that in the case of the smaller scale, the deviation of the spectra from the target is quite large.

scholarly journals Investigation of PbMg target characteristics by a laser mass-spectrometer

2005 ◽  
Vol 23 (4) ◽  
pp. 521-526 ◽  
Author(s):  
R.T. KHAYDAROV ◽  
G.R. BERDIYOROV ◽  
U. KUNISHEV ◽  
M. KHALMURATOV ◽  
E. TOJIKHONOV ◽  
...  
Keyword(s):  
Mass Spectrometer ◽  
Heavy Ions ◽  
Energy Spectra ◽  
Plasma Ions ◽  
Laser Mass Spectrometer ◽  
Pb Ions ◽  
Charge States ◽  
Target Characteristics

Characteristics of two-element (PbMg) laser generated plasma ions were studied using a mass-spectrometer. It was found that increasing the fraction of Mg leads to widening of the energy spectra of Pb ions by more than a factor of two, while the intensity of Pb ions of all charge states does not depend on the Mg fraction. This effect is explained by the friction existing between light and heavy ions during their expansion away from the target.

scholarly journals MATHEMATICAL MODELING OF ENERGY SPECTRA FORMED AT ACCELERATING THE ELECTRONS BY RELATIVISTIC INTENSIVE GAUSSIAN AND LAGUERRE LASER PULSES

2021 ◽  
Vol 2021 (1) ◽  
pp. 4-12
Author(s):  
Oleg Shiryaev
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Laser Radiation ◽  
Electronic Spectra ◽  
Laser Pulses ◽  
Intense Laser ◽  
Energy Spectra ◽  
Optical Pulses ◽  
Intense Laser Radiation ◽  
Relativistic Equations

A mathematical model is constructed that describes the propagation of laser pulses in vacuum, taking into account the corrections due to their finite duration. On its basis, using Newton relativistic equations with the corresponding Lorentz force, the energy spectra of an ensemble of electrons are simulated by relativistically intense laser radiation. The characteristics of these spectra are studied for the cases of Gaussian and Laguerre optical pulses. Electronic spectra in the fixed angular ranges are localized around the relativistic maxima in the case of Gaussian pulses, but are substantially non-monoenergetic in the case of Laguerre pulses.

scholarly journals ANALYSIS OF ENERGY SPECTRA BY THE VORTEX METHOD WITH ARTIFICIAL TURBULENCE

2004 ◽  
Vol 3 (2) ◽  
pp. 143
Author(s):  
Y. Ogami ◽  
K. Nishiwaki ◽  
Y. Yoshihara
Keyword(s):  
Turbulent Flows ◽  
Kinematic Viscosity ◽  
Vortex Method ◽  
Energy Spectra ◽  
Mean Square ◽  
Characteristic Parameters ◽  
Mean Velocity ◽  
Velocity Fluctuations ◽  
Inlet Condition ◽  
The Given

First, in order to use as an inlet condition for turbulent simulation, a method is presented which produces numerically an artificial turbulence, namely, a series of velocity fluctuations of which frequency is Gaussian, and energy spectrum and root mean square correspond to the given ones. Besides, the fluctuation data are determined by the characteristic parameters of turbulent flows such as the inlet mean velocity, the kinematic viscosity, the Kolmogorov scale and the integral time scale. Our examples show excellent accuracy and flexibility of the method. Secondly, the vortex method has been studied to see the ability of the method to deal with turbulent flows. It is found that the energy spectra produced by this agree well with the ones given as the inlet condition, and that the vortex method is able to produce turbulent flows with the given parameters described above.

Energy spectra of geomagnetically trapped oxygen ions

1999 ◽  
Vol 31 (1-6) ◽  
pp. 595-600
Author(s):  
M. Leicher ◽  
R. Beaujean ◽  
W. Enge
Keyword(s):  
Energy Spectra ◽  
Oxygen Ions

scholarly journals MODEL OF THE INTERACTION OF OXYGEN IONS O+-O+2 WITH DIPOLAZATION FRONTS DURING ELECTROMAGNETIC TURBULENCE IN THE EARTH’S MAGNETOTAIL

2019 ◽  
Vol 47 (1) ◽  
pp. 94-96
Author(s):  
E.I. Parkhomenko ◽  
V.Yu. Popov ◽  
H.V. Malova ◽  
L.M. Zelenyi
Keyword(s):  
Particle Acceleration ◽  
Numerical Model ◽  
Time Scale ◽  
Energy Spectra ◽  
Field Variation ◽  
Plasma Particle ◽  
Oxygen Ions ◽  
A Current ◽  
Different Time Scales ◽  
Accelerated Particles

The paper is devoted to studying processes of plasma particle acceleration in the process of magnetic dipolazations in a current sheet of Earth’s magnetotail. A numerical model is constructed that allows evaluation of oxygen ions O+ – O+2 acceleration in two possible scenarios: (A) Passage of multiple dipolazation fronts; (B) Passage of fronts followed by largescale electromagnetic turbulence. The energy spectra of two types of accelerated particles are obtained: oxygen O+ and O+2. It is shown that, at different time scales, predominant variety acceleration of particle populations occurs in scenarios (A)–(B). Thus the closer the time scale of the field variation to the ions gyroperiod, the more effective is the transfer of energy from fields to particles. Oxygen ions O+2 are accelerated efficiently in multiple dipolazation process (B) and increase energy up to 3 MeV , whereas ions O+ - up to 1.7 МeV. It is shown that accounting for electromagnetic fluctuations, accompanying magnetic dipolazation, may explain the appearance of streams of oxygen ions with energies greater than 3MeV in Earth’s magnetotail.

Determination of the mean multiplicity of particles produced in a nuclear interaction using the method of the inverse problem

1968 ◽  
Vol 46 (10) ◽  
pp. S718-S721
Author(s):  
V. A. Astafiev
Keyword(s):  
Inverse Problem ◽  
Simple Model ◽  
Energy Range ◽  
Good Accuracy ◽  
Nuclear Interaction ◽  
Energy Spectra ◽  
Low Energies ◽  
The Mean ◽  
The Given

The possibility of the determination of the mean multiplicity of secondaries, n(E), with the aid of the cascade characteristics has been studied using the nuclear cascade with one-type particles as an example. For the simple model of interaction with the inelasticity coefficient k = 1 the energy spectra of particles in the showers produced by the particles of various energies have been calculated. The function n(E) has been restored in the higher-energy range on the assumption that the calculated spectra are known from the "experiment," and the function n(E) at low energies has been measured within good accuracy. Estimates of the accuracy of the cascade data necessary for determining n(E) within the given accuracy are presented.

Low Background Digital Coincidence Spectrometer – A Tool for Investigation of Positron Annihilation in Flight

2012 ◽  
Vol 331 ◽  
pp. 53-73 ◽  
Author(s):  
Jakub Čížek ◽  
M. Vlček ◽  
F. Lukáč ◽  
O. Melikhova ◽  
I. Procházka ◽  
...  
Keyword(s):  
Positron Annihilation ◽  
High Purity ◽  
Relativistic Theory ◽  
Gamma Ray ◽  
Energy Spectra ◽  
Two Dimensional ◽  
Low Background ◽  
Coincidence Spectrometer ◽  
Digital Spectrometer ◽  
Flight Measurements

A digital spectrometer for low background gamma ray spectroscopy equipped with two high purity Ge detectors and a 12-bit two channel digitizer was employed for the investigation of positron annihilation-in-flight. Measurements were performed for positrons emitted by 68Ge/68Ga and 22Na radioisotopes and annihilated in Cu and Mg targets. The contribution of the two-quantum positron annihilation-in-flight was clearly resolved in coincidence two-dimensional gamma ray energy spectra. The contribution of positrons annihilated in flight has a hyperbolic shape described well by the relativistic theory.

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